THERESA May has been urged to end her “closed door approach” to Brexit with the SNP insisting that to get a good deal she must now involve all four nations in her withdrawal strategy.

Calling on the Prime Minister to secure unilaterally the rights of EU citizens living in the UK, Stephen Gethins, the Nationalists’ Europe spokesman, said: “It’s time that the UK Government’s closed door approach to Brexit comes to an end and if Theresa May is serious about securing a good deal, then that good deal will only come about with the full involvement of all four nations across the UK and that represents the views and positions of all the devolved administrations when it comes to protecting the economy, jobs, businesses and immigration needs.”

The Fife MP insisted there was now a growing consensus and momentum behind a four-nation approach, including support from business leaders, and the UK Government should move now to ensure a place at the table for all the devolved governments.

“The SNP Scottish Government was the only government to put forward a sensible and coherent compromise paper that seeks to protect Scotland's interests as the rest of the UK prepares to leave the EU. That compromise EU paper must be set out in the negotiating room with a strong voice for Scotland present at the table.

"SNP MPs in Westminster will continue to oppose the Tory Government's obsession with pursuing a hard Brexit and seek to build cross-party support for a position that all parties can rally behind," he added.

Meantime, Lord Mandelson, the former business secretary and EU commissioner, has offered to serve on any cross-party commission to advise on Brexit. He supported Sir John Major, the former Prime Minister, as a potential chairman of the group.

The Labour peer urged the Government to reach beyond party lines to find a “consensus British position” on its aims for the negotiations with the EU27.

A commission has been proposed by, among others, Nicola Sturgeon, the First Minister, and William Hague, the former Conservative leader.